Avoid the Marsaglia effect in 3D

For a longer discussion, see the associated Chromium issue.

BUG=chromium:423311
LOG=y
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/662513004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24721 ce2b1a6d-e550-0410-aec6-3dcde31c8c00